qmail-smtpd problem was:Re: Email plug meeting

[D. Taylor]

As a general rule of thumb, what I've found when
you attempt an action that should do something
immediately, but instead it pauses for about sixty
seconds, nine times out of ten the issue is name
resolution (DNS).

Check your hostname.  Does "hostname" print out something
like "fu.bar.com", or does it just spit out "fu"?
Try doing nslookup / dig (with the authoritative flag
set) to try to resolve (A, PTR, and MX) info about
yourself and the remote host you're talking to.  IFF
there's nothing obviously wrong with DNS, try dumping
DNS altogether.  Else, fix your DNS.

I haven't tried qmail in a non-DNS environment, but for
troubleshooting, to disable DNS what you want to do is
rename /etc/resolv.conf, kill the nameserver on the local
host (if one is running), add appropriate entries for
all of the hosts you'll be dealing with to /etc/hosts,
and temporarily disable bind in /etc/nsswitch.conf.
Restart qmail and it will (should) use only /etc/hosts
for its name resolution.


D

On Fri, 17 Mar 2000, Nick Estes wrote:

> Date: Fri, 17 Mar 2000 14:55:57 -0700
> From: Nick Estes <nick@wiredglobal.net>
> Reply-To: plug-discuss@lists.PLUG.phoenix.az.us
> To: plug-discuss@lists.PLUG.phoenix.az.us
> Subject: qmail-smtpd problem  was:Re: Email plug meeting
> 
> I've done some poking around on the mail server in question, and here's
> the main piece of information that seems to narrow it right down to a
> qmail problem (or things immediately affecting qmail):  When logged into
> the mail server, telnet localhost smtp comes up right away, and the
> server behaves fine, but telnetting to it's external IP doesn't.  It
> hangs for about a minute and then finally responds (which is the same
> behaviour they are seeing from the outside).  So it's not a network
> related problem, and no other services on the box are affected by it, so
> it has to be something qith qmail-smtpd (or tcpserver, since this is the
> only thing tcpserver is managing).
> 
> 	--Nick
> 
> 
> "D. Taylor" wrote:
> > 
> > More details would be nice, but the only thing that
> > I can think of off the top of my head is that if
> > a particular remote host is down or appears to be
> > under heavy load, qmail is designed to "be gentle"
> > to the other side and back off and try again later.
> > 
> > In the past (and probably in the present, too), if
> > a major mail host went down for say, a day, then
> > came back online, she would get totally hammered
> > by remote MTAs trying to send her their queued up
> > mail all at the same time, thus creating more problems.
> > 
> > Many modern MTAs are more well-behaved.
> > 
> > D
> > 
> > On Fri, 17 Mar 2000, Diane Barrett wrote:
> > 
> > > Date: Fri, 17 Mar 2000 14:19:57 -0700
> > > From: Diane Barrett <dbarrett@desertdocs.com>
> > > Reply-To: plug-discuss@lists.PLUG.phoenix.az.us
> > > To: plug-discuss@lists.PLUG.phoenix.az.us
> > > Subject: Email plug meeting
> > >
> > > This would be of great interest to me.  We are running qmail.  It ran fine
> > > for about 8mos. Now at lest once a week SMTP stops recognizing requests for
> > > 2-6hrs. then just starts working again.  I would be interested in hearing
> > > from anyone who can help resolve issue. Thanks.
> > >
> > > Diane Barrett
> > > Desert Document Services, Inc.
> > >
> > >
> > > _______________________________________________
> > > Plug-discuss mailing list  -  Plug-discuss@lists.PLUG.phoenix.az.us
> > > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
> > >
> > 
> > _______________________________________________
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> 
> 
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